1. Field of the Invention
The present invention relates to a device to measure the level of material in containers and, in particular, to measure the level of free-flowing solid matter or liquids having different dielectric constants.
2. Description of Related Art
The measuring of a level of oil, water and/or emulsions thereof in open or closed containers frequently presents difficulties when using known electronic sensors. When the measuring, or the evaluation of a measuring signal, is carried out as against air as the medium, coatings and incrustations, which are caused by contaminated or viscous media contained in the containers, may form on the sensors and prevent reliable measuring.